Which gas will diffuse fastest under identical conditions? MCQ with Answer and Explanation

Which gas will diffuse fastest under identical conditions?
A. NH₃
B. N₂
C. CO₂
D. O₂
Answer: Option A
Solution (By JKExamLibrary)
Rate of diffusion is inversely proportional to the square root of molar mass (Graham's law). Lighter gases diffuse faster. Molar masses: NH₃ = 17, N₂ = 28, O₂ = 32, CO₂ = 44 g/mol. Therefore NH₃ has the lowest molar mass and diffuses fastest. This law also explains why the smell of perfume spreads quickly. NH₃ is lighter than air and would rise.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More chemistry Questions

Question #1
Diamond is not a good conductor of electricity because:
A. It is made of carbon.
B. All valence electrons are involved in covalent bonds.
C. It is very hard.
D. It has a layered structure.

Correct Answer: Option B


Explanation:
In diamond, each carbon atom is sp³ hybridized and forms four strong covalent bonds, utilizing all four valence electrons. No free electrons are available for conduction. Graphite has free delocalized electrons per carbon, making it a conductor.

This question belongs to: Science chemistry
Question #2
The enzyme that hydrolyzes urea into ammonia and CO₂ is:
A. Urease
B. Zymase
C. Lipase
D. Pepsin

Correct Answer: Option A


Explanation:
Urease catalyzes urea hydrolysis: (NH₂)₂CO + H₂O → 2NH₃ + CO₂. It is found in bacteria and plants. Used in clinical tests for urea.

This question belongs to: Science chemistry
Question #3
Hard water does not produce good lather with soap because it contains:
A. Chloride ions
B. Sodium ions
C. Potassium ions
D. Calcium and magnesium ions

Correct Answer: Option D


Explanation:
Calcium (Ca²⁺) and magnesium (Mg²⁺) ions react with soap anions to form insoluble precipitates (scum), preventing lather. Sodium and potassium soaps are soluble and lather well. So detergents are preferred in hard water because their calcium/magnesium salts are soluble. Hardness is measured in terms of CaCO₃ equivalent.

This question belongs to: Science chemistry